1. Field of the Invention
The present invention relates to, a measuring method or a control method for measuring (in vivo measurement) or controlling, in a living state, dynamical life activities changing at high speed in a life object such as an animal including a human or a plant or changes thereof by a non-contact and noninvasive method.
2. Description of the Related Art
An example of dynamical life activities changing at high speed in a life object is activities of the nervous system. Methods for measuring an intracerebral activity include a blood oxygen analyzing of blood with near infrared light (hereinafter referred to as “Conventional Technique 1”) and oxygen analyzing of blood with a functional Magnetic Resonance Imaging (fMRI) method (hereinafter referred to as “Conventional Technique 2”), which are representative examples of conventional techniques.
According to Conventional Technique 1, the oxygen concentration in blood is measured by use of a change of a near infrared light absorbing spectrum of oxyhemoglobin and deoxyhemoglobin (see Non Patent Document 1). That is, the oxyhemoglobin which is a particular hemoglobin bonding to an oxygen molecule has a maximum absorption at a wavelength of 930 nm, and the deoxyhemoglobin which is other particular hemoglobin separated from an oxygen molecule has maximum absorption at wavelengths of 760 nm and 905 nm. A head is illuminated with each light of 780 nm, 805 nm, and 830 nm as a light source (a semiconductor laser) for measurement, and changes in intensity of respective beams of transmitted light are measured. Signals relating to cortex areas of the brain at 3 to 4 cm in depth are hereby obtained from a surface of the head.
Except the method using near infrared light, there is a method using Nuclear Magnetic Resonance to perform the measurement of the oxygen concentration in blood. That is, when adsorption of oxygen molecules is switched to release of oxygen molecules, electron orbitals in hemoglobin molecules are changed, which changes magnetic susceptibility and shortens T2 relaxation time of MR.
According to Conventional Technique 2, a location (activation area) where an oxygen consumption rate has increased in the nervous system is estimated by use of this phenomenon (see Non Patent Documents 2 and 3). When this method is used, a measurement result can be obtained by a computer process and the oxygen concentration distribution in blood in the head can be exhibited in a three-dimensional manner.
Meanwhile, as a method for controlling dynamical life activities in a life object, there has been known medical treatment.